An inflatable vehicle occupant restraint, such as an air bag, is inflated to protect an occupant of a vehicle upon the occurrence of a vehicle collision. The air bag is part of a vehicle occupant restraint system which further includes a collision sensor and an inflator. The collision sensor senses vehicle conditions which indicate the occurrence of a collision. When the collision sensor senses a collision-indicating condition of at least a predetermined threshold level, the inflator is actuated. The inflator then emits inflation fluid which inflates the air bag into the vehicle occupant compartment to restrain an occupant of the vehicle from forcefully striking parts of the vehicle as a result of the collision.
An air bag and an inflator are typically assembled together as parts of an air bag module which is separate from the collision sensor. In addition to the air bag and the inflator, the module includes a deployment door or cover which extends over the air bag and the inflator to conceal those parts of the module from the vehicle occupant compartment. As the inflation fluid emitted from the inflator begins to inflate the air bag, it moves the air bag forcefully outward against the deployment door. The deployment door is ruptured by the force of the fluid pressure in the air bag, and is moved out of the path of the air bag as the inflation fluid continues to inflate the air bag outward into the vehicle occupant compartment.
An air bag module is located in the vehicle adjacent to the vehicle occupant compartment, such as in the instrument panel or on the steering column. When the module is located on the steering column, it is attached to the steering wheel on the steering column.